Yūki Miyata was the original manager for Hodokubo High School's baseball team until hospitalization for a lifelong terminal illness required extended medical care, ending her active role. Her deep connection with childhood friend Minami Kawashima began in infancy. Witnessing Minami's passionate play, particularly a game-winning hit in elementary school, spurred Yūki to join the baseball club. This fueled her dream of guiding the team to the national tournament, rooted in her admiration for Minami's early talent.

Despite her absence, Yūki stayed informed on the team's progress, communicating regularly with Minami. She offered insights into members like pitcher Keiichirō Asano's background and scorekeeper Ayano Hōjō's shyness. Ayano openly expressed strong admiration for Yūki, indicating meaningful bonds within the management team.

Yūki's health deteriorated significantly during the team's prefectural tournament finals. She passed away just as Hodokubo advanced toward their national goal, profoundly impacting Minami and triggering an emotional collapse requiring teammate intervention. Before her death, her conversations with Minami grew increasingly solemn and foreboding, suggesting awareness of her limited time.

Her legacy endured through Minami's continued application of Peter Drucker's management principles, which Yūki had indirectly initiated. The team's foundational objective of reaching the nationals remained a testament to her original vision. Yūki's influence extended beyond logistics, embodying the emotional catalyst that unified the team's efforts after her passing.